Macro assertables::assert_fn_err_string_eq

macro_rules! assert_fn_err_string_eq {
    ($function:path, $left:expr, $right:expr $(,)?) => { ... };
    ($function:path, $left:expr, $right:expr, $($arg:tt)+) => { ... };
}

Assert one function ok() is equal to another function ok().

• When true, return ().

• Otherwise, call panic! with a message and the values of the expressions with their debug representations.

Example

fn f(i: i32) -> Result<bool, String> { Err(format!("{:?}", i)) }
assert_fn_err_string_eq!(f, 1, 1);
//-> ()

// fn f(i: i32) -> Result<bool, String> { Err(format!("{:?}", i)) }
// assert_fn_err_string_eq!(f, 1, "b);
//-> panic!("assertion failed: `assert_fn_err_string_eq(fn, left, right)`\n  left input: `1`\n right input: `2`\n  left output: `\"1\"`\n right output: `\"2\"`")

This macro has a second form where a custom message can be provided.